Vehicle side body structure

ABSTRACT

To reduce the amount of intrusion into the vehicle interior at the time of a side collision and achieve weight reduction, a vehicle side body structure includes a pillar member that partitions a side part opening of a body into a front part and a rear part, and the pillar member includes an upper member made of high-tensile steel and a lower member joined to the upper member, made of high-tensile steel, and having a rigidity lower than the upper member. The upper member has a reinforcing member made of high-tensile steel with a tensile strength higher than the upper member and the lower member and the lower half of the reinforcing member are shaped to have a lower bending rigidity against bending toward the inside in the vehicle width direction, toward the lower end of the reinforcing member.

TECHNICAL FIELD

The present invention relates to a vehicle side body structure and, moreparticularly, to a vehicle side body structure having a pillar memberincluding an upper member, a lower member, and a reinforcing member.

BACKGROUND ART

Various structures for suppressing deformation of pillar members intothe vehicle interior have been conventionally developed to ensure thesafety of occupants at the time of a side collision of a vehicle. Forexample, in a side body structure of a vehicle described in PatentDocument1, approximately an upper two-thirds of a pillar reinforcementof a center pillar is formed by an upper member and a lower one-third ofthe pillar reinforcement is formed by a lower member, the upper memberand the lower member are joined to each other, the cross-sectionalshapes of the upper member and the lower member are made different sothat the bending rigidity against bending toward the vehicle interior isdifferent between the upper member and the lower member, the angle ofbending deformation of the lower member is larger than the angle ofbending deformation of the upper member as a deformation mode at thetime of a side collision, thereby reducing the maximum amount ofdisplacement of the center pillar into the vehicle interior.

Specifically, each of the upper member and the lower member has a sidewall part extending along the side surface of the body and a pair offront and rear vertical wall parts extending toward the inside in avehicle width direction from the front and rear ends of the side wallpart. The pair of vertical wall parts of the lower member is inclined sothat the interval of the pair of vertical wall parts is larger towardthe inside in the vehicle width direction and the inclination angle ofthe vertical wall parts of the lower member is larger than in thevertical wall parts of the upper member.

In addition, structures for improving rigidity and absorbing an impactneed to be provided in other portions of the body to address the case inwhich the center pillar does not behave as assumed.

In recent years, due to improvement of press molding technology, suchas, for example, improvement of tailored blank technology, it ispossible to integrate plate members having different thicknesses anddifferent strengths or perform press molding with plate memberssuperposed on each other to improve the rigidity of a part thereof.Application of such technology to the center pillar can improve theaccuracy of deformation of the lower part and the upper part of thecenter pillar at the time of a side collision.

PRIOR ART DOCUMENTS Patent Documents

Patent Document 1: JP 2010-173562A

SUMMARY OF THE INVENTION Problem to be Solved by the Invention

Since the pair of vertical wall parts of the lower member is inclined sothat the interval of the pair of vertical wall parts is larger towardthe inside in the vehicle width direction in the vehicle side bodystructure in Patent Document1, the width in the vehicle front-reardirection of the lower member becomes large, thereby increasing the sizeof the center pillar.

However, to improve the accuracy of deformation of the center pillar atthe time of a side collision while preventing an increase in the size ofthe center pillar, plate members having different thicknesses may bejoined to each other, the plate members may be partially superposed oneach other, or a plate member such as a high-tensile material that hasdifferent strength may be joined. Even in such a case, conditions havingeffects on the bending rigidity of the center pillar need to be setappropriately in advance.

An object of the present invention is to provide a vehicle side bodystructure including a pillar member that includes an upper member, alower member having a rigidity lower than the upper member, and areinforcing member provided in the upper member, that reduces the amountof intrusion into the vehicle interior at the time of a side collision,and achieves weight reduction.

Means for Solving the Problem

According to the present invention, provided is a vehicle side bodystructure including a pillar member including an upper member, a lowermember that is joined to the upper member and has a rigidity lower thanthe upper member, and a reinforcing member provided in the upper member,the pillar member partitioning a side part opening of a body into afront part and a rear part, in which a lower half of the reinforcingmember is shaped to have a lower bending rigidity against bending towardan inside in a vehicle width direction, toward a lower end of thereinforcing member.

In the structure described above, the rigidity of the upper member isset higher than the rigidity of the lower member and the reinforcingmember is provided in this upper member, so the upper member has arigidity higher than the lower member. Since the lower half of thereinforcing member is shaped to have a lower bending rigidity againstbending toward the inside in the vehicle width direction toward thelower end of the reinforcing member, the bending rigidity of the lowermember is set lower than the bending rigidity of the upper member andthe reinforcing member while ensuring the continuity of the bendingrigidity across the whole length of the upper member. Since the bendingrigidity of the upper member can be adjusted via the reinforcing member,weight reduction in the pillar member can be achieved.

Accordingly, since the upper member undergoes bending deformation andmainly the lower member is crushed at the time of a side collision, theangle of bending deformation of the lower member toward the vehicleinterior is larger than the angle of bending deformation of the uppermember and a portion near the border between the upper member and thelower member intrudes into the vehicle interior at a maximum amount.Since the portion near the border between the upper member and the lowermember comes close to the lower part by setting the length of the uppermember longer than the length of the lower member, the amount ofintrusion of the pillar member into the vehicle interior at the time ofa side collision can be reduced.

As described above, since the roles of the upper member and the lowermember at the time of a side collision are divided and the differencebetween the strengths thereof does not become so large, the behavior ofthe pillar member at the time of a side collision becomes stable.

The present invention may have various preferred embodiments describedbelow.

Preferably, the reinforcing member is set to have the bending rigidityagainst the bending toward the inside in the vehicle width direction viaa front-rear width in a vehicle front-rear direction (second aspect).

In this structure, the bending rigidity can be set freely by setting thefront-rear width of the reinforcing member.

Preferably, the upper member has a pair of front and rear ridge partsextending in a vehicle up-down direction, and the reinforcing member hasa wide part provided across the pair of front and rear ridge parts and anarrow part that extends downward from the wide part and covers one ofthe pair of front and rear ridge parts (third aspect).

In this structure, the upper member can be reinforced by using thereinforcing member at minimum while ensuring the integrity of thereinforcing member.

Preferably, the pillar member has a plurality of hinge coupling parts towhich a hinge that supports a door is coupled, a portion of thereinforcing member that corresponds to an uppermost one of the hingecoupling parts is formed by a lower end portion of the wide part, andthe narrow part extends downward from the lower end portion of the widepart (fourth aspect).

In this structure, the effects of the invention described above can beobtained while suppressing intrusion of the pillar member near thebeltline corresponding to the uppermost one of the hinge coupling partsinto the vehicle interior at the time of a side collision.

Advantage of the Invention

As described above, various effects can be obtained by the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating a vehicle side body structureaccording to an embodiment of the present invention to which a door hasbeen mounted.

FIG. 2 is a perspective view illustrating the vehicle side bodystructure.

FIG. 3 is a side view illustrating a center pillar and a peripheralstructure thereof.

FIG. 4 is a side view illustrating a reinforcing member to be mounted tothe center pillar.

FIG. 5 is a side view illustrating the main parts of an impact barmounted to the door and the center pillar.

FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 3.

FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 3.

FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 3.

FIG. 9 is a cross-sectional view illustrating the main part including across-sectional view taken along line IX-IX in FIG. 5.

FIG. 10 is a cross-sectional view illustrating the center pillar in theposition of an upper door hinge.

FIG. 11 is a cross-sectional view illustrating the center pillar in theposition of a lower door hinge.

FIG. 12 is an explanatory diagram used to describe a deformation mode ofthe door.

FIG. 13 is an explanatory diagram used to describe a deformation mode ofthe door according to a comparative example.

MODES FOR CARRYING OUT THE INVENTION

An embodiment of a vehicle side body structure according to the presentinvention will be described below with reference to the drawings.

FIGS. 1 to 3 illustrate a vehicle side body structure 1 of a 4-doorsedan car, this vehicle side body structure 1 has a side part opening 2,this side part opening 2 is partitioned into a front side opening 2 aand a rear side opening 2 b by a pillar member 3 of a center pillar (notillustrated), and the front side opening 2 a and the rear side opening 2b are closed by side doors 4 in an openable and closable manner.However, the side door for closing the front side opening 2 a is notillustrated in FIG. 1. It should be noted here that arrows F, L, and Uindicate the front side, the left side, and the upper side.

In the following description, the vehicle side body structure 1 on theright side of an automobile is assumed as an example.

The vehicle side body structure 1 has a roof side rail 5 and a side sill6 that extend in the front-rear direction and these members form theupper side part and the lower side part of the side part opening 2. Themiddle parts in the front-rear direction of the roof side rail 5 and theside sill 6 are coupled to each other by the pillar member 3 extendingin the up-down direction.

It should be noted here that the center pillar includes the pillarmember 3 illustrated in FIGS. 1 and 2, an inner panel (not illustrated)joined to the inner surface inside in the vehicle width direction ofthis pillar member 3, and an outer panel (not illustrated) that coversthe outer surface side of the pillar member 3. The center pillar isformed to have a larger front-rear width in the front-rear directiontoward the lower portion. The upper end portion of the pillar member 3is joined to the roof side rail 5 and the lower end portion of thepillar member 3 is joined to the side sill 6.

The pillar member 3 includes an upper member 7, a lower member 8 joinedto the upper member 7 and having a rigidity lower than the upper member7, and the lower end of the upper member 7 and the upper end of thelower member 8 are welded to each other in a joint line 9. The verticallength of the upper member 7 is longer than the vertical length of thelower member 8 and is, for example, approximately three-fourths (¾) ofthe whole length of the pillar member 3 and the vertical length of thelower member 8 is approximately one-quarter (¼) of the while length ofthe pillar member 3. However, the ratios described are not limited to ¾and ¼.

The upper member 7 and the lower member 8 are formed by thin platemembers made of high-tensile steel, the upper member 7 is formed by aplate member thicker than in the lower member 8, and the upper member 7has a rigidity higher than the lower member 8.

As illustrated in FIGS. 6 to 8 and 10, the upper member 7 has a sidewall part 7 a oriented in the vehicle front-rear direction, a pair offront and rear vertical wall parts 7 b and 7 c extending toward theinside in the vehicle width direction from the front and rear ends ofthe side wall part 7 a, and the joint parts between the side wall part 7a and the pair of vertical wall parts 7 b and 7 c are a pair of frontand rear ridge parts 7 d and 7 e extending in the vehicle up-downdirection. Similarly, as illustrated in FIGS. 3, 5, and 11, the lowermember 8 has a side wall part 8 a oriented in the vehicle front-reardirection and a pair of front and rear vertical wall parts 8 b and 8 cextending toward the inside in the vehicle width direction from thefront and rear ends of the side wall part 8 a and the joint partsbetween the side wall part 8 a and the pair of vertical wall parts 8 band 8 c are a pair of front and rear ridge parts 8 d and 8 e extendingin the vehicle up-down direction.

As illustrated in FIGS. 3 to 5, a reinforcing member 10 is welded to theouter surface in the vehicle width direction of the upper member 7. Thisreinforcing member 10 is formed by a thin plate member made ofhigh-tensile steel with a higher tensile strength than the upper member7 and the lower member 8. When the pillar member 3 is manufactured, thematerial of the reinforcing member 10 is welded to the surface of thematerial of the upper member 7, the upper end of the material of thelower member 8 is welded to the lower end of the material of the uppermember 7, and these materials are press-molded by tailored blanktechnology.

The upper end portion of the reinforcing member 10 and the upper endportion of the upper member 7 are joined to the roof side rail 5. Thereinforcing member 10 has a wide part 11 that straddles the pair offront and rear ridge parts 7 d and 7 e of the upper member 7 and anarrow part 12 that extends downward from the wide part 11 and coversonly one of the front and rear ridge parts (rear ridge part 7 e in theembodiment) 7 d and 7 e. The front-rear width in the front-reardirection of the wide part 11 is set larger than the front-rear width inthe front-rear direction of the narrow part 12. The vertical length ofthe wide part 11 is, for example, approximately three-fourths of thewhole length of the reinforcing member 10 and the vertical length of thenarrow part 12 is, for example, approximately one-quarter of the wholelength of the reinforcing member 10.

It should be noted here that a triangular opening 10 a is formed in theportion of the wide part 11 close to the upper end and three longopenings 10 b are formed in series with bridge parts 10 c providedtherebetween in the portion extending downward from this opening 10 a.

The bending rigidity of the reinforcing member 10 against bending towardthe inside in the vehicle width direction is adjusted via the openings10 a and 10 b described above.

As illustrated in FIG. 4, since the bending rigidity of the reinforcingmember 10 against bending toward the inside in the vehicle widthdirection is set via the front-rear width in the vehicle front-reardirection, the lower half of the reinforcing member 10 is shaped to havea gradually lower bending rigidity against bending toward the inside inthe vehicle width direction toward the lower end of the reinforcingmember 10.

Although the front-rear width of the side wall part 7 a of the uppermember 7 has effects on the bending rigidity of the upper member 7, thefront-rear width of the side wall part 7 a is maximized in the vicinityof a hinge coupling part 13 and reduces toward the lower part from thevicinity of the hinge coupling part 13.

As illustrated in FIGS. 3, 10 and 11, the pillar member 3 has two hingecoupling parts 13 and 14 to which a hinge that supports the side door 4is coupled, and the portion of the reinforcing member 10 thatcorresponds to the upper hinge coupling part 13 is formed by the lowerend portion of the wide part 11 and the narrow part 12 extends downwardfrom the lower end portion of this wide part 11. The lower end portionof the wide part 11 has two bolt holes 10 d for the upper hinge couplingpart 13. The lower hinge coupling part 14 is formed in the vicinity ofthe upper end of the lower member 8.

As illustrated in FIGS. 5 and 9, in the side door 4 disposed adjacentlyto the pillar member 3, an impact bar 15 that ensures the rigidity ofthe portion of the side door 4 near the beltline and transmits a sidecollision load to the pillar member 3 is provided. In the state in whichthe side door 4 is closed, a front end portion 15 a of the impact bar 15overlaps with the upper member 7 and the lower member 8 in a vehicleside view.

To reliably transmit the side collision load from the impact bar 15 tothe upper member 7 and the lower member 8, the front end portion 15 a ofthe impact bar 15 overlaps with the vertical wall parts 7 c and 8 c onthe vehicle rear side of the upper member 7 and the lower member 8 inthe vehicle side view.

As illustrated in FIG. 5, so as to distribute the side collision loadapplied to the pillar member 3 from the impact bar 15 to the uppermember 7 and the lower member 8, the front end portion 15 a of theimpact bar 15 has a region 16 a of the upper member 7 in which thereinforcing member 10 is present, a region 16 b of the upper member 7 inwhich the reinforcing member 10 is not present, and a region 16 c thatcovers the lower member 8 in the vehicle side view.

As illustrated in FIGS. 3 and 5, the pillar member 3 has a harnesspass-through opening 17 through which harnesses for a power window and aspeaker pass and the front end portion 15 a of the impact bar 15 coversat least a part of the harness pass-through opening 17 in the vehicleside view to protect the harnesses. The opening 17 is formed in thevicinity of the lower end of the upper member 7, that is, the vicinityof the joint line 9 and this opening 17 appropriately reduces thebending rigidity of the upper member 7.

Next, the operation and the effect of the vehicle side body structure 1described above will be described.

Since the rigidity of the upper member 7 is set higher than the rigidityof the lower member 8 and this upper member 7 has the reinforcing member10 made of high-tensile steel, the rigidity of the upper member 7 andthe reinforcing member 10 is higher than that of the lower member 8.Since the lower half of the reinforcing member 10 is shaped to have alower bending rigidity against bending toward the inside in the vehiclewidth direction toward the lower end of the reinforcing member 10, thebending rigidity of the lower member 8 is set lower than the bendingrigidity of the upper member 7 and the reinforcing member 10 whileensuring the continuity of the bending rigidity across the whole lengthof the upper member 7. Since the bending rigidity of the upper member 7can be adjusted via the reinforcing member 10, weight reduction in thepillar member 3 can be achieved.

Accordingly, since the upper member 7 undergoes bending deformation andmainly the lower member 8 is crushed when a side collision load isapplied, the angle of bending deformation of the lower member 8 towardthe vehicle interior is larger than the angle of bending deformation ofthe upper member 7 and a portion near the border between the uppermember 7 and the lower member 8 intrudes into the vehicle interior at amaximum amount.

Since the border portion between the upper member 7 and the lower member8 comes close to the lower part by setting the length of the uppermember 7 longer than the length of the lower member 8, the maximumamount of intrusion of the pillar member 3 into the vehicle interior atthe time of a side collision can be reduced. As described above, sincethe roles of the upper member 7 and the lower member 8 at the time of aside collision are divided and the difference between the strengthsthereof do not become so large, the behavior of the pillar member 3 atthe time of a side collision becomes stable.

Specifically, as illustrated in FIG. 12, when a side collision load isapplied to a center pillar 3P from the outside in the vehicle widthdirection as indicated by an arrow P, the roof side rail 5 and the sidesill 6 move toward the inside in the vehicle width direction and thepillar member 3 is deformed to the state indicated by the dot-dash linethrough the state indicated by the dotted line.

The deformation mode of the pillar member 3 at this time enters thestate in which a gradual bending occurs in a border part A between theupper member 7 and the lower member 8, the upper member 7 undergoesbending deformation toward the vehicle interior and the lower member 8is deformed toward the vehicle interior mainly in a crushed manner, andthe angle of the bending deformation of the lower member 8 is largerthan the angle of the bending deformation of the upper member 7.Accordingly, an amount D of intrusion of the pillar member 3 into thevehicle interior in the border part A is maximized.

FIG. 13 illustrates the deformation mode according to a comparativeexample in which a middle part of a pillar member 3′ of a center pillar3P′ is sharply bent. An amount D′ of intrusion of the pillar member 3′into the vehicle interior in this case is significantly larger than theamount D of intrusion in FIG. 12.

Since the bending rigidity of the reinforcing member 10 against bendingtoward the inside in the vehicle width direction is set via thefront-rear width in the vehicle front-rear direction, the bendingrigidity can be set freely by adjusting the front-rear width of thereinforcing member 10.

Since the reinforcing member 10 has the wide part 11 that straddles thepair of front and rear ridge parts 7 d and 7 e and the narrow part 12that extends downward from this wide part 11 and covers only one (rearridge part 7 e in the embodiment) of the front and rear ridge parts 7 dand 7 e, the upper member 7 can be reinforced by using the reinforcingmember 10 at minimum while ensuring the integrity of the reinforcingmember 10.

Since the portion of the reinforcing member 10 corresponding to theupper hinge coupling part 13 is formed by the lower end portion of thewide part 11 and the narrow part 12 extends downward from the lower endportion of this wide part 11, the above effects can be obtained whilesuppressing intrusion of the pillar member 3 near the beltlinecorresponding to the upper hinge coupling part 13 into the vehicleinterior at the time of a side collision.

Since the front end portion 15 a of the impact bar 15 provided in theside door 4 overlaps with both the upper member 7 and the lower member 8in the vehicle side view when the side door 4 is closed, the collisionload applied to the impact bar 15 at the time of a side collision actson both the upper member 7 and the lower member 8 without concentratingon one of the upper member 7 and the lower member 8, thereby stabilizingthe behavior of the pillar member 3 at the time of a side collision anddeforming the pillar member 3 in a desired deformation mode.

Since the front end portion 15 a of the impact bar 15 covers the region16 a of the upper member 7 in which the reinforcing member 10 ispresent, the region 16 b of the upper member 7 in which the reinforcingmember 10 is not present, and the lower member 8 in the vehicle sideview, and the front end portion 15 a of the impact bar 15 overlaps witha structural discontinuous part including the border part through whicha shift from the region 16 a in which the reinforcing member 10 ispresent to the region 16 b in which the reinforcing member 10 is notpresent is made and the border part in which the upper member 7 isjoined to the lower member 8, the pillar member 3 can be deformed in adesired deformation mode by distributing the load from the impact bar 15to the upper member 7 and the lower member 8 at the time of a sidecollision.

Since the pillar member 3 has the harness pass-through opening 17 andthe front end portion 15 a of the impact bar 15 covers at least a partof the harness pass-through opening 17 in the vehicle side view, theharnesses that pass through the opening 17 can be protected by the frontend portion 15 a of the impact bar 15.

Since the front end portion 15 a of the impact bar 15 overlaps with thevertical wall parts 7 c and 8 c on the vehicle rear side of the uppermember 7 and the lower member 8 in the vehicle side view, the load atthe time of a side collision can be reliably transmitted to the uppermember 7 and the lower member 8 by transmitting the load from the frontend portion 15 a of the impact bar 15 to the vertical wall parts 7 c and8 c on the vehicle rear side of the upper member 7 and the lower member8 at the time of a side collision.

Next, examples in which the embodiment is partially modified will bedescribed.

1) Although the upper member, the lower member, and the reinforcingmember of the pillar member have been formed by members made ofhigh-tensile steel, the lower member may be formed by a member made ofnormal steel. The material of the pillar member is not limited to thematerial in the embodiment described above.

2) Although the reinforcing member has been formed by a single member,the reinforcing member may be formed by a plurality of members.

3) Other than the above, those skilled in the art may make an additionto the embodiment described above as appropriate.

It should be understood that the embodiments herein are illustrative andnot restrictive, since the scope of the invention is defined by theappended claims rather than by the description preceding them, and allchanges that fall within metes and bounds of the claims, or equivalenceof such metes and bounds thereof, are therefore intended to be embracedby the claims.

DESCRIPTION OF REFERENCE CHARACTERS

-   -   1: vehicle side body structure    -   2: side part opening    -   3: pillar member    -   4: side door    -   7: upper member    -   7 a: side wall part    -   7 b, 7 c: vertical wall part    -   7 d, 7 e: ridge part    -   8: lower member    -   8 a: side wall part    -   8 b, 8 c: vertical wall part    -   8 d, 8 e: ridge part    -   10: reinforcing member    -   11: wide part    -   12: narrow part    -   13, 14: hinge coupling part    -   15: impact bar    -   15 a: front end portion    -   16 a: region in which reinforcing member is present    -   16 b: region in which reinforcing member is not present

The invention claimed is:
 1. A vehicle side body structure comprising: apillar member including an upper member, a lower member that is joinedto the upper member and has a rigidity lower than a rigidity of theupper member, and a reinforcing member provided in the upper member, thepillar member partitioning a side part opening of a body into a frontpart and a rear part, wherein a lower half of the reinforcing member isshaped to have a lower bending rigidity against bending toward an insidein a vehicle width direction, toward a lower end of the reinforcingmember, the upper member has a pair of front and rear ridge partsextending in a vehicle up-down direction, and the reinforcing member hasa wide part provided across the pair of front and rear ridge parts and anarrow part that extends downward from the wide part and covers one ofthe pair of front and rear ridge parts.
 2. The vehicle side bodystructure according to claim 1, wherein the reinforcing member is set tohave the bending rigidity against the bending toward the inside in thevehicle width direction via a front-rear width in a vehicle front-reardirection.
 3. The vehicle side body structure according to claim 1,wherein the pillar member has a plurality of hinge coupling parts towhich a hinge that supports a door is coupled, a portion of thereinforcing member that corresponds to an uppermost one of the hingecoupling parts is formed by a lower end portion of the wide part, andthe narrow part extends downward from the lower end portion of the widepart.